Dr. Ahmed G. Abo-Khalil

Electrical Engineering Department

filter

a network, usually composed of inductors and capacitors (for lumped
circuit), or transmission lines of varying length and characteristic
impedance (for distributed circuit), that passes AC signals over a
certain frequency range while blocking signals at other frequencies. A
bandpass filter passes signals over a specified range (flow to fhi), and rejects frequencies outside this range. For example, for a DBS
receiver that is to receive satellite transmitted microwave signals in a
frequency range of 11 GHz to 12 GHz, a band-pass filter (BPF) would
allow signals in this frequency range to pass through with minimum
signal loss, while blocking all other frequencies. A low-pass filter
(LPF)

would allow signals to pass with minimum signal loss as long as
their frequency was less than a certain "cutoff frequency" above which
significant signal blocking occurs.

an operator that transforms image intensity Ix of pixel x into a different intensity îx,
depending on the values of a set of (usually neighboring) pixels (which
may or may not include x). Filtering is performed to enhance
significant features of an image or to remove nonsignificant ones or
noise. filter bank a set of filters consisting of a bank of analysis
filters and a bank of synthesis filters. The analysis filters decompose
input signal spectra into a number of directly adjacent frequency bands
for further processing, and the synthesis filters recombine the signal
spectra from different frequency bands.